Zoysia grass plant named `SS-500`

ABSTRACT

A new and distinct variety of Zoysia japonica turfgrass, called `SS-500`, is characterized by its color, long and wide leaf blades, large stolons, an open growth habit, and rapid establishment rate.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct variety of aperennial Zoysia grass, discovered on a Brazilian turf farm in Sao Paoloduring a routine field inspection. The grass was found in a productionfield of a common Brazilian grass known as `Wild Zoysia` (unpatented).The new grass is believed to be a sport of `Wild Zoysia` due to itscolor and its larger leaf size and longer node length compared to `WildZoysia`. The novel grass, termed `SS-500`, was propagated asexually inSao Paolo, Brazil. `SS-500` is a distinct, asexually propagated varietyof Zoysia grass. `SS-500` is the varietal designation of this new grass.The name `SS-500` may also designate this plant in commerce.

SUMMARY OF THE INVENTION

`SS-500` is a attractive green Zoysia grass, with an open growth habit.It is characterized by the combination of its color, open growth habit,and large leaf blade length and width.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 compares stolons of `SS-500` and `SS-300`. `SS-300` is anothernew variety of Zoysia grass, and is the subject of co-pending U.S. PlantPatent application Ser. No. 09/028,031. A metric ruler is provided forscale.

FIG. 2 compares stolons of `SS-500` and Zoysia cultivars `Meyer`, `ElToro`, and `SS-300`, next to a metric scale.

FIG. 3 shows a runner of `SS-500` that grew to over 30 inches in lessthan a month.

FIG. 4 shows a plug of `SS-500`.

FIG. 5 shows `SS-500` in the field at three months. Compare this to FIG.6.

FIG. 6 shows `El Toro` in the field at three months, grown under thesame conditions as the `SS-500` depicted in FIG. 5.

FIG. 7 shows the seedhead of `SS-500`.

FIG. 8 shows one view of the root structure of `SS-500`.

FIG. 9 shows one view of the root structure of `SS-500`.

FIG. 10 provides a comparison of the `SS-500` (top) and `SS-300`(bottom) cultivars.

FIG. 11 shows a close-up of stem color of `SS-500`.

FIG. 12 is a gel showing DNA fingerprint analysis of `SS-500` incomparison to other varieties of zoyziagrass using primer 8.6i.M=molecular size markers in base pairs. Areas of distinct DNAamplification differences are indicated by small arrows.

FIG. 13 is a gel showing DNA fingerprint analysis of `SS-500` incomparison to other varieties of zoyziagrass using primer 10.6e.M=molecular size markers in base pairs. Areas of distinct DNAamplification differences are indicated by small arrows.

DETAILED DESCRIPTION OF THE VARIETY

The following is a detailed description of the new Zoysia grass varietyknown as `SS-500`, based upon observations of the plant grown in plugtrays and field plots. Color notations are based on The RoyalHorticultural Society Colour Chart, The Royal Horticultural Society,London.

`SS-500` is a perennial, vegetatively propagated Zoysia grass, believedto be a variety of Zoysia japonica. The parent of `SS-500` is believedto be a native Brazilian variety of Zoysia japonica, commonly known as`Wild Zoysia`. `SS-500` is a wide-bladed grass with an open growthhabit. Applicants have asexually propagated `SS-500` by means of stolonsand rhizomes. Applicants have discovered the novelty and distinctness of`SS-500` compared to other varieties of Zoysia.

`SS-500` has an open growth habit, large stolons and leaf blades, and amassive root system. Side-by-side comparisons of `SS-500` to variety `ElToro` (a standard for rapid growth of Zoysia) demonstrated that `SS-500`exhibits rapid growth; complete coverage can occur within five to sixmonths after planting, compared to `El Toro` which takes nine to tenmonths under similar conditions. Each variety was planted in 8'×8' plotsusing 4-inch prerooted grass plugs planted 12-inches on center todetermine coverage rates.

`SS-500` is characterized by its large leaf blade width and length, opengrowth habit and large stolon size, and other characteristics describedherein. `SS-500` has a rapid establishment rate, high tolerance todrought, good fall color retention rates, and good tolerance toherbicides MSMA and 2-4-D.

DIMENSIONS AND GROWTH HABIT

`SS-500` was discovered on a Brazilian turf farm in a production fieldof a common Brazilian grass known as `Wild Zoysia`. The new grass wasinitially believed to be an `off-type`, or sport, of `Wild Zoysia` dueto its color and its larger leaf size (compared to `Wild Zoysia`).`SS-500` exhibits an open growth habit and large leaf width and length,compared to other Zoysia grasses. `SS-500` is low growing during theinitial stage of coverage. After the ground is covered the grass becomesupright and open in habit. The grass spreads by stolons and rhizomesthat form an open uniform groundcover. The root structure of `SS-500` ismassive and deep, with large individual roots.

The leaf blade width and length of `SS-500` are larger than `El Toro` orother comparable types of Zoysia. `SS-500` has a more open growth habit,fewer seedheads, and longer as well as wider leaf blades than `WildZoysia`, `El Toro` Zoysia (U.S. Plant Pat. No. 5,845), or `Meyer`(unpatented) Zoysia. Further comparison testing to variety `El Toro`, astandard for rapid growth of Zoysia, demonstrates that `SS-500` canexhibit 100% coverage within five to six months of planting as comparedto `El Toro`, which takes nine to ten months under similar conditions.This characteristic may be beneficial to the turf industry, as providinga grass suitable for erosion control. Runners of `SS-500` have beenmeasured at 30 inches in length after a three-week growth period, asshown in FIG. 3. The growth and morphology of `SS-500` is furthercharacterized in Table I, which presents data regarding blade width,blade length, internode length, stolon width, and spike length for`SS-500` in comparison with other varieties of Zoysia.

                  TABLE I                                                         ______________________________________                                        Length and Width Data                                                         Blade        Blade    Internode                                                                              Stolon Spike                                   Width                                           Length                        (mm)                                            (mm)                          ______________________________________                                        `SS-300`                                                                              1.9-2.3  30-40    18-25  1.0-1.5                                                                              16-18                                 `SS-500`                                                                                                                        30-40                       `El Torro`                                                                                                                      27-30                       `Meyer`                                           24-28                       `Emerald`*                                                                                                                      12-14                       ______________________________________                                         *unpatented                                                                   Reference: Test plots located at Elsberry Greenhouse in Ruskin, FL.           Reference: Test plots located at Bethel Farms in Arcadia, FL.                 8' × 8' plots                                                           Plugged by Elsberry Greenhouse in Ruskin, FL on 2/03/98.                      Plugged by Bethel Farms in Arcadia, FL on 2/18/99.                            Material attained by special permit USDA Quarantine Lab, Beltsville, MD. 

`SS-500`, unlike many Zoysia grasses, can be easily mowed with a rotarymower due to its large blade size and its open growth habitat. Thistrait is important as it reduces general maintenance and allows the useof less expensive mowing equipment.

`SS-500` spreads by stolons and rhizomes and forms an open uniformgroundcover. The stolons are grey-purple in color (183B). Stolons areabout 4 to 5 millimeters in width with nodes about 3 to 3.5 centimetersapart. The nodes of `SS-500` root adventitiously. New leaves are rolledinto bud shoots. Mature leaves are about 5 to 5.5 millimeters in widthand can reach 14 centimeters in length. Mature leaves have a dark greencolor on both upper and lower surfaces corresponding to 137A. The leaveshave hairs along the edges, which are more concentrated along the end ofthe leaf. The leaves taper to a point. The culm has the same dark greencolor (137A) as the leaf blade. The collar is large and continuous. Theinflorescence is a single spike at the top of the stem. The anther iswhite (155D) and the stigmas are green-white (157C) in color. The seedpods are greyed purple at the top portion (i.e., tip) and fade to agreen-white color at the bottom portion of the seed pod (183C and 157C,respectively). The root structure is massive and deep, with largeindividual roots.

`SS-500` demonstrates an extended season as compared with other Zoysiagrasses, The `SS-500` variety exhibits early greening in the Spring andlate Fall color retention.

These and other features and characteristics of the `SS-500` cultivarare apparent from the figures provided herein.

REPRODUCTION

After its initial discovery, `SS-500` was removed from the productionfield and transplanted into plug trays for further trials and testing.After several series of cuttings and transplantings were made, `SS-500`retained the color, size, and node length characteristics that wereoriginally noted. `SS-500` was taken transplanted to field plots forexamination.

During examination of `SS-500` transplanted to field plots, it was notedthat `SS-500` spread at a rate faster than `Wild Zoysia` (30-40%faster). Further testing and evaluation determined that the root systemof `SS-500` is more aggressive than that of `Wild Zoysia`, and equallydense to that of `Wild Zoysia`. Roots of `SS-500` are generally largerin diameter than those of `Wild Zoysia`. Further comparison testing tovariety `El Toro`, a standard for rapid growth of Zoysia, demonstratesthat `SS-500` can exhibit 100% coverage within five to six months ofplanting, compared to `El Toro` which takes nine to ten months undersimilar conditions. More extensive data regarding coverage rates of`SS-500` in comparison with other Zoysias are presented in Table 2.Other turf characteristics are provided in Table 3 and Table 4.

                  TABLE 2                                                         ______________________________________                                        Percent Coverage Data (%)                                                                  30      60      90    120   150                                  Plant #                                             Days                      ______________________________________                                        `SS-300`                                                                              20       30      40    55    80    95                                 `SS-500`                                                                                       35 20   45    60    85    100                                `El Torro`                                                                              20     25      35    50    65    80                                 `Meyer`          250     30    45    55    70                                 `Emerald`*                                                                                     20    20                                                                              25    35    45    55                                 ______________________________________                                         *unpatented                                                                   Reference: Test plots located at Elsberry Greenhouse in Ruskin, FL.           Reference: Test plots located at Bethel Farms in Arcadia, FL.                 8' × 8' plots                                                           Plugged by Elsberry Greenhouse in Ruskin, FL on 2/03/98.                      Plugged by Bethel Farms in Arcadia, FL on 2/18/99.                            Material attained by special permit USDA Quarantine Lab, Beltsville, MD. 

                  TABLE 3                                                         ______________________________________                                        Zoysia Variety Evaluation                                                     Turf         Seedhead Turf     Turf   Disease                                 Density      Presence Color    Quality                                                                              Presence                                ______________________________________                                        `El Toro`                                                                             78.8     17.5     6.25   7.63   22.5                                  `SS-500`                                                                              92.5     18.8     6.25 8.00                                                                            15.0                                         `Meyer` 36.3     0.0      8.13   6.25   58.5                                  `SS-300`                                                                              93.8     0.0      6.38   7.38   53.8                                  `Emerald`                                                                             17.5     0.0      7.38   6.63   58.8                                  Rating  0-100%   0-100%   1-9    1-9    1-100%                                Scale                     1 =  light                                                                           1 = poor                                                               9 = dark                                                                             9 = good                                     Rating  7/24/99  7/24/99  7/24/99                                                                              7/24/99                                                                              7/24/99                               Date                                                                          ______________________________________                                         Evaluations performed at Sod Solutions Coastal Research Center,               Charleston, South Carolina.                                              

                  TABLE 4                                                         ______________________________________                                        Zoysia Variety Evaluation                                                             Turf      Stolon     Plug    Seedhead                                         Quality   Regrowth   Mortality                                                                             Presence                                 ______________________________________                                        `El Toro`                                                                              7.88     29.3       0.0     30.0                                     `SS-500`                                                                                       8.00                                                                           47.0       0.0     85.0                                     `Meyer`          8.38                                                                           4.3        0.0     11.3                                     `SS-300`                                                                              8.63      150.0      0.0     1.3                                      `Emerald`                                                                                     7.00                                                                            26.5       0.3     10.0                                     Rating  1-9       Number     Percent 1-100%                                   Scale            1 = poor                                                                      9 = good                                                     Rating  5/7/99    5/7/99     5/7/99             5/7/99                        Date                                                                          ______________________________________                                                Internode Blade      Turf    Plug                                             Length    Width      Density Width                                    ______________________________________                                        `El Toro`                                                                                   26.0                                                                              3.20       7.5     15.47                                    `SS-500`                                                                              35.0      5.23       10.0    15.90                                    `Meyer`          34.0                                                                           3.10       0.0     12.60                                    `SS-300`                                                                                        2.280      11.3    15.50                                    `Emerald`                                                                             12.0      1.20       1.3     14.22                                    Rating  mm        mm         1-100%  cm                                       Scale                                                                         Rating          5/22/99                                                                         5/22/99    5/22/99 5/22/99                                  Date                                                                          ______________________________________                                         Evaluations performed at Sod Solutions Coastal Research Center,               Charleston, South Carolina.                                              

Sprigs of `SS-500` establish roots quickly, within three to six days,and the root system is massive and deep. Other advantages bothphysically and morphologically are apparent from the figures providedherein.

`SS-500`, unlike many Zoysia grasses, can be easily mowed with a rotarymower due to its large blade size and its open growth habit. This traitreduces general maintenance and allow the use of less expensive mowingequipment.

`SS-500` can be propagated from sod, plugs, sprigs, stolons, tillers orrhizome pieces. Because `SS-500` regrows from rhizomes, ribbons orstrips of grass are not required to be left in the field for successfulre-growth after sod harvesting. Seed stability is undetermined at thistime, but indications suggest that there is little to no viability.

Asexual propagation of `SS-500` was carried out in the state of SaoPaolo, Brazil. Asexual reproduction of `SS-500` by rhizomes and tillershas established that the characteristics and combination ofcharacteristics noted in `SS-500` are transmitted during succeedingpropagations.

ENVIRONMENTAL TOLERANCES

`SS-500` is similar to other Zoysia japonica varieties in that itrequires full sun to slight shade. Its hardiness zone is unknown; coldhardiness studies are currently underway. `SS-500` has been noted toturn brown after heavy frost, but has excellent fall color retention.

`SS-500` has good drought tolerance, most likely due to the massive rootsystem.

DISEASE RESISTANCE AND SUSCEPTIBILITY

`SS-500` has resistance to leaf spot disease and only limitedsusceptibility to armyworms as compared with other grasses.

DNA FINGERPRINT ANALYSIS

DNA fingerprint analysis was carried out on `SS-500` at the Universityof Tennessee using the methods described in U.S. Pat. No. 5,413,909 andby Caetano-Anolles et al., (1991) Bio/Technology 9:553. Cultivar`SS-300` and standards `Meyer`, `El Toro`, and `Emerald` (unpatented)were also analyzed. Genomic DNA was isolated from freshly grownmaterial. No evidence of diseased tissue or weeds was detected. Severalyoung blades of grass were ground in liquid nitrogen and DNA extracted.DNA was extracted in duplicate from the supplied samples. The DNA wasquantified by fluorimetry, then was diluted and amplified using thestandard high primer-low template DNA ratio using DNA amplificationfingerprinting (DAF) as described in U.S. Pat. No. 5,413,909 andCaetano-Anolles et al., (1991) Bio/Technology 9:553. Stoffel fragment ofTaq™ DNA polymerase (Perkin Elmer Corp.) was used to amplify genomicDNA. Primers 8.6i and 10.6e were used. Amplification occurred in an MJRPT200 thermocycler, using the optimized DAF amplification program DAF15.This program involves fast ramping, high annealing temperature (55° C.),and an extension step at 72° C. Resulting amplification products wereresolved using SUPERGEL™ polyacrylamide gel electrophoresis (Bassam andBentley, (1995) Biotechniques 19:568) and visualized by silver stainingas described in U.S. Pat. No. 5,643,479 and Bassam et al., (1991) Anal.Biochemistry 196:80.

The DNA was extracted in duplicate from the samples. The DNA was dilutedand amplified as described above. Duplicate amplification products wereseparated by polyacrylamide gel electrophoresis.

Two gels showing the result of DNA analysis are shown in FIG. 12 andFIG. 13, using primer 8.6i or 10.6e, respectively. About 15 majoramplification products, seen as strong bands, and about 30 minor onesare commonly seen. The lanes on the sides represent molecular sizemarkers (1000, 700, 500 (doublet), 400, 300, 200 and 100 bp) used todetermine the size of the amplification products.

Using primer 8.6i (FIG. 12), several polymorphic bands were seen thatdistinguish `SS-500` from the other Zoysia cultivars. The primer 8.6iclearly distinguishes the `Meyer`, `El Toro` and `Emerald` standards,e.g., in the 400-500 bp region.

The `SS-300` and `SS-500` samples are similar to each other, but clearlydifferent. The differences between these two cultivars are even morepronounced with the 10.6e primer (FIG. 13).

The results of the fingerprinting analysis indicated that both `SS-500`and `SS-300` are most closely related to `El Toro`. The `SS-500` and`SS-300` varieties appear to be related, but are clearly distinct fromeach other. Primers 8.6i and 10.6e showed clear polymorphisms forseveral major bands. Areas of distinct DNA amplification differences areindicated by small arrows in FIG. 12 and FIG. 13.

That which is claimed is:
 1. A new and distinct variety of Zoysiajaponica grass plant named `SS-500`, substantially as described andillustrated, which has an open growth habit, rapid coverage rate, andlarge leaf blades.